/**
 * 本库提供几个常用方法：
 * 1、Zxl.Libs.uniEncode(text);	将中文进行Unicode编码并输出
 * 2、Zxl.Libs.base64Encode(text); 将文字进行base64编码并输出
 * 3、Zxl.Libs.base64Decode(text); 将经过base64编码的文字进行base64解码并输出
 * 4、Zxl.Libs.utf8Encode(text); 将文字进行utf-8编码并输出
 * 5、Zxl.Libs.utf8Decode(text); 将经过utf-8编码的文字进行utf-8解码并输出
 */
var Zxl = window.Zxl || {};

Zxl.Libs = function(){
	//base64编码字符集
	this.base64EncodeChars = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/";
	//base64解码字符集
    this.base64DecodeChars = new Array(
		-1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
		-1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
		-1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, 62, -1, -1, -1, 63,
		52, 53, 54, 55, 56, 57, 58, 59, 60, 61, -1, -1, -1, -1, -1, -1,
		-1, 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14,
		15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, -1, -1, -1, -1, -1,
		-1, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40,
		41, 42, 43, 44, 45, 46, 47, 48, 49, 50, 51, -1, -1, -1, -1, -1);
};


/**
 * 此方法实现中文向Unicode的转码，与Jre中的"native2ascii"命令一样
 * @param {String} text 需要进行转码的字符串
 * @return {String} Unicode码
 */
Zxl.Libs.prototype.uniEncode = function(text){
    text = escape(text.toString()).replace(/\+/g, "%2B");
    var matches = text.match(/(%([0-9A-F]{2}))/gi);
    if (matches) {
        for (var matchid = 0; matchid < matches.length; matchid++) {
            var code = matches[matchid].substring(1, 3);
            if (parseInt(code, 16) >= 128) {
                text = text.replace(matches[matchid], '%u00' + code);
            }
        }
    }
    text = text.replace('%25', '%u0025').replace(/%/g, "\\");
    
    return text;
};

/**
 * 此方法用于将文字进行UTF-8编码
 * @param {Object} str 源码
 * @return {String} UTF-8码
 */
Zxl.Libs.prototype.utf8Encode = function(str) {
	var out, i, len, c;
	out = "";
	len = str.length;
	for(i = 0; i < len; i++) {
		c = str.charCodeAt(i);
		if ((c >= 0x0001) && (c <= 0x007F)) {
			out += str.charAt(i);
		} else if (c > 0x07FF) {
			out += String.fromCharCode(0xE0 | ((c >> 12) & 0x0F));
			out += String.fromCharCode(0x80 | ((c >> 6) & 0x3F));
			out += String.fromCharCode(0x80 | ((c >> 0) & 0x3F));
		} else {
			out += String.fromCharCode(0xC0 | ((c >> 6) & 0x1F));
			out += String.fromCharCode(0x80 | ((c >> 0) & 0x3F));
		}
	}
	return out;
};

/**
 * 此方法用于将文字进行UTF-8解码
 * @param {Object} str
 * @return {String} 原文字
 */
Zxl.Libs.prototype.utf8Decode = function(str){
    var out, i, len, c;
    var char2, char3;
    out = "";
    len = str.length;
    i = 0;
    while (i < len) {
        c = str.charCodeAt(i++);
        switch (c >> 4) {
            case 0:
            case 1:
            case 2:
            case 3:
            case 4:
            case 5:
            case 6:
            case 7:
                // 0xxxxxxx
                out += str.charAt(i - 1);
                break;
            case 12:
            case 13:
                // 110x xxxx　 10xx xxxx
                char2 = str.charCodeAt(i++);
                out += String.fromCharCode(((c & 0x1F) << 6) | (char2 & 0x3F));
                break;
            case 14:
                // 1110 xxxx　10xx xxxx　10xx xxxx
                char2 = str.charCodeAt(i++);
                char3 = str.charCodeAt(i++);
                out += String.fromCharCode(((c & 0x0F) << 12) |
                ((char2 & 0x3F) << 6) |
                ((char3 & 0x3F) << 0));
                break;
        }
    }
    return out;
};
	
/**
 * 此方法用于将文字进行base64编码
 * @param {Object} str 源码
 * @return {String} base64码
 */
Zxl.Libs.prototype.base64Encode = function(str){
    var out, i, len;
    var c1, c2, c3;
    len = str.length;
    i = 0;
    out = "";
    while (i < len) {
        c1 = str.charCodeAt(i++) & 0xff;
        if (i == len) {
            out += this.base64EncodeChars.charAt(c1 >> 2);
            out += this.base64EncodeChars.charAt((c1 & 0x3) << 4);
            out += "==";
            break;
        }
        c2 = str.charCodeAt(i++);
        if (i == len) {
            out += this.base64EncodeChars.charAt(c1 >> 2);
            out += this.base64EncodeChars.charAt(((c1 & 0x3) << 4) | ((c2 & 0xF0) >> 4));
            out += this.base64EncodeChars.charAt((c2 & 0xF) << 2);
            out += "=";
            break;
        }
        c3 = str.charCodeAt(i++);
        out += this.base64EncodeChars.charAt(c1 >> 2);
        out += this.base64EncodeChars.charAt(((c1 & 0x3) << 4) | ((c2 & 0xF0) >> 4));
        out += this.base64EncodeChars.charAt(((c2 & 0xF) << 2) | ((c3 & 0xC0) >> 6));
        out += this.base64EncodeChars.charAt(c3 & 0x3F);
    }
    return out;
};
    
/**
 * 此方法用于将文字进行base64解码
 * @param {Object} str 源码
 * @return {String} 源码
 */
Zxl.Libs.prototype.base64Decode = function(str){
    var c1, c2, c3, c4;
    var i, len, out;
    len = str.length;
    i = 0;
    out = "";
    while (i < len) {
        /* c1 */
        do {
            c1 = this.base64DecodeChars[str.charCodeAt(i++) & 0xff];
        }
        while (i < len && c1 == -1);
        if (c1 == -1) 
            break;
        /* c2 */
        do {
            c2 = this.base64DecodeChars[str.charCodeAt(i++) & 0xff];
        }
        while (i < len && c2 == -1);
        if (c2 == -1) 
            break;
        out += String.fromCharCode((c1 << 2) | ((c2 & 0x30) >> 4));
        /* c3 */
        do {
            c3 = str.charCodeAt(i++) & 0xff;
            if (c3 == 61) 
                return out;
            c3 = this.base64DecodeChars[c3];
        }
        while (i < len && c3 == -1);
        if (c3 == -1) 
            break;
        out += String.fromCharCode(((c2 & 0XF) << 4) | ((c3 & 0x3C) >> 2));
        /* c4 */
        do {
            c4 = str.charCodeAt(i++) & 0xff;
            if (c4 == 61) 
                return out;
            c4 = this.base64DecodeChars[c4];
        }
        while (i < len && c4 == -1);
        if (c4 == -1) 
            break;
        out += String.fromCharCode(((c3 & 0x03) << 6) | c4);
    }
	
    return out;
};
